// Implements a dictionary's functionality

#include <stdbool.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <strings.h>
#include <cs50.h>


#include "dictionary.h"

// Represents a node in a hash table
typedef struct node
{
    char word[LENGTH + 1];
    struct node *next;
}
node;

int number_of_words = 0;

// Number of buckets in hash table
const unsigned int N = 20000;

// Hash table
node *table[N];

// Returns true if word is in dictionary else false
bool check(const char *word)
{
    int hash_num = hash(word);

    node *p = table[hash_num];
    while (p != NULL)
    {
        int a = strcasecmp(p->word, word);
        if (a == 0)
        {
            return true;
        }
        p = p->next;
    }

    return false;
}

// Hashes word to a number
unsigned int hash(const char *word)
{
    int sum = 0;
    while(*word != '\0')
    {

        if(*word >='A' && *word < 'A'+26)
             sum=sum+(*word -'A' + 1);
        else if(*word >='a' && *word < 'a'+26)
             sum=sum+(*word -'a' + 1);
        else
             return -1;

        word++;
    }

    return sum;
}

// Loads dictionary into memory, returning true if successful else false
bool load(const char *dictionary)
{
    // Openning the dictionary file for reading
    FILE *file = fopen(dictionary, "r");
    if ( fopen(dictionary, "r") == NULL)
    {
        return false;
    }

    string word = NULL;
    while (fscanf(file, "%s", word) != EOF)
    {
        node *n = malloc(sizeof(node));
        if (n == NULL)
        {
            return 1;
            return false;
        }
        n->next = NULL;
        strcpy(n->word, word);

        //Handling collision
        if (table[hash(word)] != NULL)
        {
            n->next = table[hash(word)];

            table[hash(word)] = n;
        }
        else
        {
            table[hash(word)] = n;
        }

    }
    return true;
}

// Returns number of words in dictionary if loaded else 0 if not yet loaded
unsigned int size(void)
{
    return number_of_words;
}

// Unloads dictionary from memory, returning true if successful else false
bool unload(void)
{
    node *cursor = malloc(sizeof(node));
    if (cursor == NULL)
    {
        return 1;
        return false;
    }

    node *tmp = malloc(sizeof(node));
    if (tmp == NULL)
    {
        return 1;
        return false;
    }

    int n = 0;
    while (table[n] != NULL)
    {
        cursor = table[n]->next;

        tmp = table[n];

        free(tmp);

        tmp = cursor;
    }

    return false;
}